As the solar eclipse creeps closer, optometrists warn that permanent vision loss is a legitimate risk if you watch the eclipse without the right protection.

Unless you're in the path of full totality, which Louisville is not, you'll have to use eclipse glasses for the entire event. And fake glasses are making the rounds.

As VisionWorks' Dr. Richard Gersh explains, the moon will cover the sun by 96 percent in Louisville.

"We won't get the total eclipse here, but we'll get most of it," Gersh said. "It will be almost dark, but there will be a little sliver of light. That's all you need to get burnt. You don't need much."

Without the proper eyewear, it's enough to cause permanent damage to your eyes.

"If you look up directly, even if there's just a sliver of the sun, the light can go into the back of your eye and burn a hole in what's called the macula," Gersh said.

That would mean permanent loss to your central vision.

"The retina is the back of the eye. There's an optic nerve back there. Off to the side is the macula. So when you look at a period on a piece of paper, that central part of the macula is looking right at that dot," Gersh said. "That's your exact central fixation spot. That's the spot that gets burnt out from an eclipse if you're not protected properly."

The only way to ensure your vision is protected is by wearing the right kind of eclipse glasses.

Regular sunglasses are not enough, and experts warn of phonies in some stores and online.

Certified glasses will have an ISO certification posted on the glasses. NASA only recommends brands approved by the American Astronomical Society (AAS).

The AAS requires manufacturers to give proof of meeting ISO standards and a list of authorized re-sellers. Stores selling the certified classes include Kroger, Walmart and more than a dozen websites.

To make sure you don't buy any fakes, the AAS' entire list of reputable vendors and manufacturers can be found here.